Process for the production of resinacid condensation products



Patented Feb. 27, 1934 i i v 1,948,573

PROCESS FOR THE PRODUCTION OF RESIN- ACID CONDENSATION PRODUCTS v Ewald Fonrobert and Arthur Greth, Wiesbaden, ermany, assignors to Resinous Products &

Chemical 00., Inc., Philadelphia, Pa.

No Drawing. Application January 28, 1930, fgggal No. 424,131, and in Germany August 19,

11 Claims. (Cl. 260-98) Apart from the production of resin-acid esters (3) With amines and amides, amide combinafrom resin-acids with alcohols with higher tions are formed which may easily be separated boiling points, as for instance glycol, glycerine from the acid regenerated in this case also or and the like by merely boiling the mixture of from the salt like combination formed from the acid and alcohol with or without the addition latter and the basic amine or amide. of catalytic means, the production of derivatives (4) With acid esters of such acids, the anof natural or synthetic resin-acids till now met hydrides of which are distillable, they are transwith considerable difficulties owing to the high formed by alcoholysis in such a manner, that molecular size of the resin component and the the resin-acid ester 'is formed whilst the anreaction inertia connected therewith. There are hydride of the other acid is distilled off. known, it is true, some processes for attaining As resin-acids may be considered, in the scope this purpose, which,however, have failed so far of the present invention, all acid components to prove of any practical value whatsoever. of natural and synthetic resins, as far as-they For instance resin-acid esters are obtained from are at all capable of forming an anhydride.

15 the acids of colophony by changing them first Probably the anhydride of the acids contained into their sodium salt and treating the latter in the colophony, which is known as abietic acid with toxic agents such as alkylhalides or alkylanhydride, will possess the greatest practical sulphates. This method, however, is an exvalue. Furthermore the anhydrides of still acid tremely expensive one. The production of pure rearrangement products or derivatives of the 2 resin acid derivatives by means of the chlorides acids of the colophony should essentially be of said acids met with unsurmountable difllculconsidered, such as the anhydrides of the pyroties because most of the resin-acids are easily abietic acid, tetrahydroabietic acid etc. and likehalogenated in the nucleus, for which reason wise the anhydrides of other natural or synall reactions with halogens lead to derivatives thetic resin acids.

25 containing halogen. By a secondary splitting The production 01' the corresponding anhyoil of halogenhydracid-the reaction mixtures are drides is efiected in a manner known per se,

always colored very darkly. As a matter of fact, for instance by boiling the acids, which may have pure resin-acid derivatives apart from the prepreviously been purified more or less, with acetic viously mentioned esters from alcohols of higher anhydride. It is not absolutely necessary to free boiling points, have not become available practithe acid anhydrides formed from unaltered resin cally till now. acids for further treatment, particularly not- We now have made the surprising observation, when said anhydrides are subjected to reacthat resin-acid-anhydrides, contrary to expections during which part of the resin acid is retation, are. sufliciently capable of reaction .for generated. In such cases it will be possible to 35 reacting in a manner known per se with alcoproceed from the crude product of dehydration, hols, amines, phenols and similar bodies. This the free resin acids being only removed after observation was all the less to be anticipated the further treatment of said products. because the existence of the resin-acid-anhy- During the further treatment of the anhydrides had so far been looked upon with doubt. drides or the products containing anhydrides,

Dupont, for instance, still doubts the formation the work may be carried out with or without of the abietic acid anhydride described by Fonincreased pressure and with or without the adrobert and Pallauf, and he merely considers it dition of diluting agents. to be an abietic acid free of water. It may, As second components capable oi reaction all however, be proved, that in fact an anhydride alcohols, phenols, amides, amines without any is present, as may be gathered also from the distinction whatsoever may be considered, as

reactions upon which the present invention is well as all esters the constitutent acids of which based. are forming distillable anhydrides, The said Like other organic acid-anhydrides the resincompounds may be employed separately, in mixacid anhydrides show the following reactions: tures of homologous products, but also in any (1) Boiled with. alcohols they yield, apart desired mixture. Special results are attained m5 from regenerated resin-acid, the corresponding with combinations which are simultaneously beresin-acid ester. longing to two groups 01' bodies reacting with (2) Treated with phenols, they yield the coranhydrides, as for instance with monoethanol responding phenol-ester while a molecular proamine. 55 portion of resin-acid is regenerated. The great advantage of the process is emno Example 1 By heating French colophony for 24 hours with 2 to 3 times the quantity of acetic anhydride. and subsequent distilling oi! the volatile components an anhydrated product is obtained, from which the crystalline abietic acid anhydride having a melting point of 149 to 151* C. may be separated by repeated recrystallization.

If this abietic acid anhydride either crude or in the purified state. is mixed with such a quantity of anhydrous ethyl-alcohol in excess that a fairly saturated solution is produced, and if this solution is heated to -l50 C. under ordinary pressure with reflux during a few hours or under an increased pressure for a correspondingly shorter period, one molecule abietic acid anhydride will form one molecule abietic acid ethylester and one molecule free abietic acid. The latter may be removed from the reaction mixture by extraction with diluted alkalis.

The separation of the reaction products by fractional distillation can be carried through in the present case only under very great diniculties, owing to the boiling points being so extremely close to one another. This method will be more considered in conjunction with esters of alcohols possessing a higher boiling point (see Example 2).

The abietic acid ethylester thus obtained is purified by distillation and shows the chemical and physical properties which it is known to possess. It is, however, distinguished from the corresponding products of known processes by its high degree of purity. Above all, it is free from any inorganic components.

Example 2 Example 3 parts of abietic acid anhydride are melted together'with 100 parts of phenol and heated to -150 c. for a period of 1 to 2 hours.

From the oily reaction product the phenol in excess is distilled off or washed out by means of alkalis together with the abietic acid formed. By distilling the residue the abietic acid phenyl ester is obtained in almost neutral form.

Example 4 Abietic acid anhydride is dissolved in not too concentrated a form in a suitable solvent (anhydrous ether, anhydrous alcohol, benzol, mixtures of ether and benzol and so on). Into this solution dried ammonia gas is introduced under ordinary or increased pressure, with or without simultaneous heating, and whilst being shaken or stirred. The solvent is recovered from the reaction mixture by distillation. The residue is composed of molecular quantities of abietic acid amide and abietic acid ammonium salt.- The latter is washed out directly, shaking with acids and will then be subjected to fractional vacuum distillation. In this way the abietic acid amide is obtained in the form of an almost neutral, light colored, yellowish resin, the melting point of which lies above C.

Example 5' or decomposed by removed. The residue Erample 6 Example 7 Pyroabietic acid produced by a prolonged heating of abietic acid or colophony, is changed, according to the process described in Example 1, into the anhydride and caused to react in the manner described in Examples 1-6 with compounds of the kinds indicated there. As a result the corresponding esters or amide or anilide of the pyroabietic acid are obtained.

Example 8 In the same way as the pyroabietic anhydride of Example I, tetrahydroxy abietic acid anhydride may be employed. Tetrahydroxy abietic 128 acid is produced by oxidation of abietic acid with potassium permanganate in a known manner.

Having now particularly described and ascertained the nature of our said invention, what we claim is:

1. A process for the production of resin acid condensation products, consisting in transforming the resin acid into its anhydride by heating the said acid with the anhydride of aliphatic monocarboxylic acid of the lower fatty acid series and thereupon treating the anhydride thus formed with alcohols.

2. A process for the production of esters of colophony which comprises heating colophony with the anhydride of an aliphatic monocarboxylic acid of the lower fatty acid series, and subsequently condensing the abietic anhydride thus formed with a member of the group consisting of alcohols, and esters of alcohols which are decomposed under the reaction conditions to yield readily volatile acids.

3. A process for the production of abietic ester which comprises heating colophony with acetic anhydride and subsequently condensing 150 lie . 1,948,678 3 the reaction product thereby obtained with an reaction conditions to volatilize the acidic comalcohol. ponent of said esters.

4. A process for the production of abietic ester which comprises heating colophony with acetic anhydride and subsequently condensing the re-- action product thereby obtained with ethyl alcohol.

5. A process for the production of abietic ester which comprises heating colophony with acetic anhydride and subsequently condensing the reaction product thereby obtained with butyl alcohol.

6. A process for the production of abietic ester which comprises heating colophony with acetic anhydride and subsequently condensing the reaction product thereby obtained with phenol.

7. A process for the production of resin condensation products which comprises treating a resin acid anhydride with one of the group of alcohols, and esters of alcohols which are decomposed under the reaction conditions to yield' 9. 'A process for the production of resinacid condensation products which consists in converting the resin acid into its anhydride by heating the resin acid with the monocarboxylic acid of the lower fatty acid series, and heating the crude resin acid anhy-' dride thus obtained, containing unaltered tree resin acid, with a member of the group consisting of alcohols and esters of alcohols which are readily decomposed under the reaction conditions to volatilize the acidic component of said esters. I

10. A process for the production oi resin acid condensation products which consists in heating the resin acid with acetic anhydride; distilling anhydride of an aliphatic off the readily volatile parts, and heating the reaction product thus obtained with a member of the group consisting of alcohols, and wters of alcohols which are decomposed under the reaction conditions to volatilize the acidic component of said esters.

11. A process of the kind set forth in claim 8 characterized in that the resin acid anhydride first formed is heated at super-atmospheric pressure with a member of the group consisting of alcohols and esters decomposed under the reaction conditions to yield readily volatile aci EWALD FONROBERT. ARTHUR GRE'I'H.

of alcohols which are Ill 

